Its website also claims the product, which costs £20 for 14 servings, supports muscle tone and maintenance and contains “essential” ingredients including L-Carnitine and green tea.

It also includes the ingredient “Satiereal”, which is said to be an extract of saffron, which it is claimed can decrease compulsive snacking and sugar cravings and ­promote weight loss and positive mood.

However Sian was not impressed. She said: “This plan includes unhealthy appetite suppressors.

Dukan

Pippa is thought to follow the Dukan diet, which is based on the ‘phase’ you are in

FOLLOWERS eat dedicated foods based on which “phase” they are in.

There are four phases. The “attack” phase lasts seven days, involves eating pure protein meals and nothing else; the “cruise” phase sees you add 32 vegetables to your protein-based meals; the “consolidation” phase gradually introduces wheat and dairy; and the “stabilisation” phase allows you to eat three tablespoons of oat bran per day.

It claims to help people reach their “true weight” which you should be able to maintain.

But it is not as good as it sounds. Sian said: “You will lose weight quickly on the Dukan Diet but it will mainly be fluid.